1) Field of the Invention
The invention herein relates to improved diving fins.
2) Description of the Prior Art
The typical structure and operational details of a conventional pair of diving fins are shown in FIG. 1, wherein the longitudinal fin surface 10 of the said fins 1 is comprised of a single web section 102 disposed between fluke sections 101 along two sides. When the diver executes the posterior extension and anterior bending of both legs (conventionally consisting of an alternating upward and downward fluttering action), the two said fluke sections 101 directly support the web section 102 during the aquatic kicking sequence and enables the objective of diver mobility. Undeniably, the single web section 102 of the conventional fins that enables aquatic kicking propulsion possesses practical value and provides functional performance and, furthermore, is currently in widespread use among a majority of divers. However, the inventor of the invention herein discovered several shortcomings that were observed over a period of long-term utilization, each of which can be feasibly improved.
1. To reinforce the web section 102 during aquatic kicking, specifically against contortion due to water drag that results in an incapability to generate thrust, the two fluke sections 101 supporting the web section 102 must be of a relatively hard composition such that when the diver articulates both legs into posterior extension for aquatic kicking and the greater active extent of the fin surface 10 is an inclined disposition, the fin surface 10 and the two fluke sections 101 with which it is formed as a single structural entity and, furthermore, the rigidly configured longitudinal web section 102 must also be in an inclined disposition such that water is kicked at an oblique angle. However, as is well-known by all, the angle at which the said web section 102 generates maximum aquatic kicking efficiency is one that is perpendicular to the traveling direction of the diver. Given the oblique angle of aquatic kicking attack of the said web section 102, the reactive force (i.e., thrust) generated is not proportional to the aquatic kicking power delivered by the diver and results in less than optimal aquatic kicking efficiency.
2. As per the said shortcoming, since the fin surface 10 is in an inclined disposition, the said web surface 102 is accordingly at an oblique angle during aquatic kicking and consequently cannot provide a reactive force (thrust) that is proportional to the aquatic kicking power applied, therefore, to maintain underwater traveling speed, the diver must increase the rate of aquatic kicking, which obviously results in the drawbacks of a greater dissipation of physical strength and an easier onset of fatigue.
3. Since the said planar longitudinal web section 102 and the relatively hard fluke sections 101 are formed as a single structural entity that is rigidly configured, when the diver articulates both legs forward and upward preparatory to aquatic kicking by anterior bending, the forward and upward flexing of the planar web section 102 encounters relatively high fluid drag and, as such, the obvious shortcomings affecting diver articulation are the need use more strength and an inability to effectively increase speed.
4. Since the said two fluke sections 101 are relatively hard constructs, they are capable of supporting the single, large surface area of the web section 102 during the articulation of both legs during aquatic kicking. However, the relatively hard composition of the said fluke sections 101 obviously affects the degree of pliability of the fin surface 10, which in turn influences the degree of agility and control, resulting in stiffness and lack of smoothness.
As conveyed above, the structure of said conventional diving fins has several shortcomings that are manifested during actual utilization and, furthermore, require improvement.
The primary objective of the invention herein is to provide improved diving fins, wherein a flexile second web surface is disposed at the approximate center portion of a longitudinal web section. As such, when the diver articulates both legs rearward and downward for aquatic kicking by posterior extension, the said second web surface is automatically displaced forward by the force of water resistance and then reverts to a nearly perpendicular angle as the rigidness of a first web surface follows in coordination during the kicking sequence, with the power articulated by the legs not only capable of kicking efficiency that produces a maximum reactive force (thrust) and increases diver speed, but at the same time also allows for a reduction in kick rate, thereby conserving physical strength and delaying the onset of fatigue.
Another objective of the invention herein is to provide improved diving fins, wherein when the diver articulates both legs forward and upward preparatory to the next aquatic kick by anterior bending, since the said second web surface is automatically displaced rearward by the force of water resistance and a diverting hole provides for the passage of water flow, viscous drag is effectively reduced and enables the saving of strength.
Yet another objective of the invention herein is to provide improved diving fins, wherein the second web surface of the said web section is capable of flexing forward in coordination with the first web surface when both legs are articulated into posterior extension to produce optimal efficiency during the aquatic kicking sequence and, furthermore, capable of flexing rearward when both legs are articulated into anterior bending to effectively reduce viscous drag encountered preparatory to the next aquatic kick. Consequently, the fluke sections disposed along the two sides of the web section can be of a softer composition, enabling the fin surface of the fins have a greater degree of pliability such that aquatic kicking articulation and control is more agile and natural.
Still another objective of the invention herein is to provide improved diving fins that are simple and convenient in terms of structure, fabrication, and utilization and which allows the diver to enjoy efficient strength conservation and higher speed performance while articulating both legs in the process of aquatic kicking. As such, the present invention meets the requirements of actual utilization, is ideal and progressive and, furthermore, the said improved diving fins are unprecedented.